Suture-anchoring implanted medical devices engineered from bioresorbable metal alloys

Abstract

Herein described are suture-anchoring implanted medical devices formed from a bioresorbable metal alloy that may be used to secure soft tissue to bone. The metallic bioresorbable tissue anchoring devices of the present invention are optimally configured such that all portions of the device are resorbed over a short predetermined period of time while maintaining their tissue anchoring capability and preventing the generation of loose foreign bodies therefrom.

What is claimed: 
     
       1. A suture anchoring implant device for affixing a soft tissue graft to a prepared socket in a target boney surface, wherein the device has a generally tubular construction, with a proximal portion having a plurality of cross sections and proximal end and a distal portion having a cross-section and distal end, further wherein the device:
 (a) has an outer surface provided with a plurality of integral threads characterized by one or more major diameters and one or more minor diameters; 
 (b) has an inner surface defining a central lumen that extends from the proximal to the distal end of the device, wherein the proximal portion of the central lumen is provided with an integral torque-receiving feature that allows the transmission of torque to the device necessary to drive the device into the prepared socket; 
 (c) is formed from a bioresorbable metallic alloy; and 
 (d) wherein the cross-section of the distal portion of the device is heavier than one of the plurality of cross-sections of the proximal portion of the device so as to ensure that the plurality of proximal cross-sections are absorbed first and the generation of loose bodies is prevented. 
 
     
     
       2. The suture anchoring implant device of  claim 1 , wherein the diameter of the central lumen is stepped such that the interior diameter of the proximal portion is greater than the diameter of the distal portion. 
     
     
       3. The suture anchoring implant device of  claim 1 , wherein the cross-sectional area of the proximal portion of said central lumen is greater than the cross-sectional area of the distal portion of said central lumen. 
     
     
       4. The suture anchoring implant device of  claim 1 , wherein the device further includes a laterally extending suture-retaining member positioned across said central lumen. 
     
     
       5. The suture anchoring implant device of  claim 4 , wherein said laterally extending suture-retaining member is within the distal portion of said central lumen. 
     
     
       6. The suture anchoring implant device of  claim 1 , wherein each of said plurality of integral threads has a height defined the major diameter of the thread minus the minor diameter of the thread. 
     
     
       7. The suture anchoring implant device of  claim 6 , wherein the respective heights of each of said plurality of integral threads is substantially identical. 
     
     
       8. The suture anchoring implant device of  claim 6 , wherein the respective heights of each of said plurality of integral threads taper from proximal to distal end. 
     
     
       9. The suture anchoring implant device of  claim 6 , wherein each of said plurality of integral threads has a width defined as the measurement across the thread at half the height of said thread, wherein the ratio of thread width to thread height is greater that 0.3. 
     
     
       10. The suture anchoring implant device of  claim 9 , wherein the ratio of thread width to thread height is greater than 0.5. 
     
     
       11. The suture anchoring implant device of  claim 10 , wherein the ratio of thread width to thread height is greater than greater than 0.7. 
     
     
       12. The suture anchoring implant device of  claim 11 , wherein said integral torque-receiving feature is a polygonal recess. 
     
     
       13. The suture anchoring implant device of  claim 1 , wherein said integral torque-receiving feature is one or more axially extending slots. 
     
     
       14. The suture anchoring implant device of  claim 1 , wherein bioresorbable metallic alloy is selected from the group consisting of magnesium-based, iron-based and zinc-based alloys. 
     
     
       15. The suture anchoring implant device of  claim 1 , wherein the device further includes a bioactive therapeutic agent. 
     
     
       16. The suture anchoring implant device of  claim 15 , wherein said bioactive therapeutic agent is in the form of a surface coating. 
     
     
       17. The suture anchoring implant device of  claim 15 , wherein said bioactive therapeutic agent is incorporated into a plurality of pores of the bioresorbable metallic alloy from which the device is formed. 
     
     
       18. The suture anchoring implant device of  claim 15 , wherein said bioactive therapeutic agent is selected from the group consisting of peptides, nucleic acids, hormones, chemical drugs, or other biological agents, useful for enhancing the healing process.